Many different types of searches are used for exploring and developing geological resources, such as oil, gas or mineral deposits. These searches are typically localized, requiring time-consuming search and evaluation teams. In some techniques used in oil and gas exploration, geological research requires laborious hands-on, on-the-ground technical data collection using gradiometers and magnetometers. Remote sensing is typically not involved in these searches, except for a cursory classification of geostrata, for example, used in slope determination.
In the last few years, commercial satellites, such as the IKONOS satellite system, have delivered commercial image data at a very high spatial resolution. For example, the IKONOS system records four channels of multi-spectral data at four meter resolution, and one pan chromatic channel at one meter resolution. Thus, the IKONOS system can deliver near photographic high resolution satellite imagery of almost any location in the world. As a result, the volume of earth-observation imagery has greatly increased.
Some oil and mineral commercial exploratory services provide remote sensing and aircraft data collection for the geological resource community by intensely analyzing contour maps. An example of this type of system is the Falcon™ airborne gravity gradiometer (AGG) from BHPBilliton that measures minute changes in the earth's gravity to explore different terrains. Gravity data compliments magnetics data and provides insights to gain access to new terrains, prioritize targets, reduce exploration time and costs, and compliment magnetics, EM and radiometrics data. In a typical device, the gradiometer unit has two gradiometers and experiences different aircraft accelerations (e.g., reference ellipsoid, latitude, earth tide and isostatic effects). The measured gradient is the subtraction of one gradiometer response from the other. As a result, most of the corrections cancel out. This unit obtains raw data, processes it with digital signal processing circuits, and provides self-gradient correction, terrain correction, and transformation to GDD and gD.
Another technique for facilitating oil and gas exploration is disclosed in U.S. Pat. No. 6,502,037, which discloses gravity and magnetic data inversion using vector and tensor data, including the use of seismic imaging and geopressure production analysis for oil, gas and mineral exploration and development. Complicated mathematics are used to analyze data fields. There is no prediction algorithm, however. In that system, geological structures are modeled by obtaining seismic data to derive an initial density model. An inversion process uses vector or tensor components of the gravity and/or magnetic data. An initial model includes a topographic or bathymetric surface and a 2D or 3D density model, that aids in distinguishing the top of any zones of anomalous density. A lower boundary of an anomalous density zone is derived by using the inversion process. The seismic data can also be processed in depth or time using a density model from the inversion.
In U.S. Pat. No. 6,508,316, the disclosed system measures the earth's local gravity and magnetic field in conjunction with global positioning coordinates. This system focuses on a localized search and does not use a prediction algorithm. Magnetometer errors during wellbore survey operations are determined on up to three axes, with or without the use of an external reference measurement of the local magnetic field. This provides an accurate result using data from a minimum number of surveys. Any difference between the corrected transform data and reference data in the earth's coordinate system is minimized to determine model parameters.
It would be advantageous, however, if a system and method could be developed that used a predictive algorithm to determine the likelihood of oil or mineral deposits within a predetermined area of the earth's surface.